Seal for sectional leading-in wires.



T. W. FREGH, JR. SEAL FOR SEGTIONAL LEADING IN WIRES. APPLICATION FILED JANJO, 1907. RENEWED SEPT. B, 1911.

1,006, 1 98, v Patented Oct. 17,1911.

2 SHE ETSSHEET 1.

T. WfI-REOH, JR.

SEAL FOR. SEGTIONAL LEADING IN WIRES.

APPLICATION FILED JAN.10, 1907. RENE-WED SEPT. 8, 1911.

1,006, 1 98, Patented-Oct. 17, 1911.

2 SHEETSSHEET 2.

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momma w- FBECH, .13., or CLEVELAND, OHIO.

SEAL FOR SECTIONAL LEADING-IN WIRES.

Spegification of Letters Iatent. Patented Oct, 17, 1911.

Application filed January 10, 190?,S erial No. 351,679. Renewed September 8, 1911.: Serial No. 648,404'.

To all whom it concern:

following is a full, clear, and exact description.

. The object of the present invention is to produce an improved form of sectional leading-in wire for incandescent lamps in which the sections shall have joints of such diameter as will permit of the wire bein securely embedded in the stem without en angering the effectiveness of the seal.

In the manufacture of the stem in which the leadin -in wires are embedded, the thickness 0 the glass stem is determined by the fixed distance between the squeezing jaws. If there are projections, spurs, or enlarged beads at the joints in thesectional leading-in wires caused by the deflected platinum ends or the uneven flow of fused copper, the glass coating or. covering will necessarily be substantially thinner over the joints than over the copper section itself. The enlarged joints being coated or covered at points by a thin skin of glass, materially thinner than the covering of the body of the copper wire behind the. joint, which latter is determined by the gaged distance between the squeezing jaws of the machine employed in forming the seal, thus come so I vide electric lamps and other articles, in.

close to the surface of the glass as to en danger the integrity of the seal.

It is the purpose of my invention to prowhich sectional leading-in wires may be advantageously employed, with a seal in which the glass covering over the joints is of substantially the same thickness as the covering over the larger conducting wire, for which latter the jaws of the machine are gaged.

Referring to the accompanying drawings which illustrate certain specifically diflerent embodiments of my invention, Figure 1 is a view of a lamp bulb, partly in section, showing the leadin -in wire jolnted according to one form 0 my novel construction. Fig. 1 is a detail section of the stem, at right angles to Fig. 1. Fig. 2 illustrates'one form of wire end, of copper, or equivalent material, used in forming a joint with the platinum. Fig. 3 is a view, partly in section, showing. the section of platinum, or equ1valent, wire inserted in theends ofthe copper SGCtIOIIS of the leading-in wire. Fig. 4 1s a perspective view showing the shape into which the end of the copper wire is made before the joint, such as shown in Figs. 2 and 3, is formed. Fig. 5 is a side view of the same. Fig. 6 is a horizontal sedtion through the end of the Wire shown in Fig. 2. Fig. 7 is a modified form in which the socket is not so nearly closed as in Fig. 2. Figs. 8 and 9 are side views, at right angles to each other, of a modification in which the end of the copper wire is perforated laterally, or, transversely, to receive the platinum section. Fig. 10 is a view of two copper sections, such as shown in Fig. 9, with the platinum section'placed in posltion for permanent attachment. Figs. 11 and 12 are side elevations illustrating two possible methods of straightening out the conductor sections shown in Fig. 10, after the platinum is permanently attached. Figs. 13 and 14 are side elevations, at right angles ,to each other, of modified forms of the copper wire in' which an opening in the form of a lateralincision has been made to receive the latinum section. Fig. 15 is a side elevat1on showing two of the copper conductors, of the form shown in Fig. 14, with the platinum section in place. Figs. 16 and 17 are side elevations ofstill another modification somewhat similar to that shown in Figs. 8 and 9 but having, instead of a lateral perforation, a notch, in the end in which the platinum section is placed.

In the various forms of joint shown the copper wire A is reduced in cross sectional mass atthe joint, where the platinum wire B is securedto the copper. In the form shown in Fig. 2, and also in the form shown in Fig. '7', a longitudinal socket is provided in the end of the wire A, by the simple expedient of flattening the end of the conductor wire, as shown in Figs. 4 and 5, and drawing the same through a suitably shapeddie, of a diameter not materially greater than thewire itself, to curl it into the form shown in Fig. 2, or as shown in Fig. 7. The mass of the copper is thus stretched out in length and decreased in cross section. When the platinum section B is placed in the socket, A thus produced, and the fusing flame is applied to the'end of the copper about the edge ofthe socket, the thin edge reduced and the fused metal, while perhaps fuses readily and adheres to the platinum making a satisfactory joint, but there is no enlarged knot or joint, or projectin spur.

In the several forms shown in igs. 8 to 17, the cross sectional mass of the copper wire is reduced at the zone of formation of the joint, in each instance, and these figures show mere modifications of sockets or pockets which I find it convenient to use in attaching the platinum to the copper wire. In all of these forms, owing to the fact that the necessary mass to be fused is reduced, fusion occurs readily and the joint is quickly formed, and there does not come into existence any enlarged bead of copper, or copper-platinum alloy, of greater diameter than the conductor wire itself. Even should the fused co per flow slightly, there could be no form 0 an enlarged bead since at such point the cross sectional mass of the wire is slightly thickening the reduced section of the copper wire, does not create a bead materially greater than the copper wire itself. In all of these forms it is to be noted that the common characteristic is that the end of the copper wire is reduced, preliminarily to fusion, so that the bead or the spurs,

formed by the fusion will be of substantially no greater diameter than the body of the wire itself and the coating of glass thereover will be of substantially the same thickness as over the body of the copper Wire, for which latter the thickness of the glass stem is sufficient.

In the formation of the seal these sectional leading-in wires are placed in the stem so that when the end of the stem is fused and pinched together the joints will be embedded in the fused glass; and the wire as a whole will of course be caught in between the end walls of the stem end, and the end will be pinched and pressed to that thickness to which the machine is-adjusted. With the forms of joints of leading-in wire which I.

have shown the glass will have substantially the same thickness over the joints of the sections as over the larger or co per wire itself. This thickness is suflicient or the purpose of an eflicient seal, and there will be no danger of the glass coating being cracked by reason of undue expansion, in any direction, of the 'oint.

Having t us described my invention, I claim:

1. A seal'for an electric lamp comprising a leading-in wire composed of sections of dissimilar metal joined together to form efiicient electrical connection, the joints between said sections having the same diameter or cross-sectional area as that of the largest component section, and a sealing material inclosing said sectional leading-in wire.

2. A seal for an electric lamp comprising a sectional leading-in wire embedded in a vitreous sealing material, one of the sections being of expansion is substantially the same as that of glass, and said sections being joined together to form an efficient electrical connection, the joints between said sections having a cross-sectional area within that of the largest component section, whereb the sealing material over the joint will e of substantially the same thickness as over the largest component section.

3. An incandescent lamp having the leading-imwire composed of ortions of dissimilar metals having di erent. cross-sections, the joint of which is of substantially of the same thickness as the larger of said portions.

In testimony whereof, I hereunto afiix my signature in the presence of two witnesses.

T. w. FREGH, JR.

Witnesses:

A. H. WALL, ALMA THOMAS.

of a material whose coefiicient 

